Unix Timestamp Converter

Unix Timestamp Converter is a free online tool for converting Unix timestamps (epoch time) to human-readable dates and converting dates back to Unix timestamps. This bidirectional converter handles timestamps in both seconds and milliseconds formats, automatically detecting which format you're using, and provides output in multiple date formats including UTC, local time, ISO 8601, and relative time formats. Perfect for developers, system administrators, database engineers, and anyone working with time-based data in Unix/Linux systems, APIs, databases, or log files. Unix timestamps represent the number of seconds that have elapsed since the Unix epoch—January 1, 1970 at 00:00:00 UTC (also known as POSIX time or Epoch time). This standardized time format is used extensively in computer systems, programming languages, databases, and web APIs because it provides a universal, timezone-independent way to represent specific moments in time as a single integer value. Common use cases include debugging API responses that return timestamps, converting database timestamp fields to readable dates for data analysis, understanding timestamps in server logs and application logs, testing date/time functionality in applications, converting timestamps from third-party APIs for display, analyzing time-series data in analytics platforms, working with JavaScript Date objects (which use milliseconds), converting timestamps in Unix shell scripts and system administration tasks, and understanding creation/modification times in file systems. The tool provides bidirectional conversion: convert timestamps to dates by entering any Unix timestamp (automatically detected as seconds or milliseconds), and convert dates to timestamps by entering dates in any common format including ISO 8601 (2024-01-15), US format (01/15/2024), European format (15/01/2024), or natural language (January 15, 2024). When converting timestamps to dates, the tool displays four useful formats: UTC time for standardized timezone-independent display, local time in your browser's timezone, ISO 8601 format (the international standard used in JSON APIs and databases), and relative time showing how long ago or how far in the future the timestamp represents. The auto-detection feature intelligently determines if your timestamp is in seconds (standard Unix timestamp) or milliseconds (used by JavaScript and some APIs) by checking if the value is reasonable for each format—timestamps before year 2100 in what appears to be seconds are automatically multiplied by 1000 for correct conversion. All conversions happen entirely in your browser using JavaScript Date objects, ensuring complete privacy with no data sent to any server. The tool works offline once loaded and doesn't require any registration or installation. Click the 'Now' button to instantly get the current Unix timestamp, useful for testing, debugging, or getting reference timestamps. Each output format includes a convenient copy button to quickly paste converted values into your code, database queries, or documentation. Unix timestamps are fundamental to computing because they're timezone-independent, easy to sort and compare, compact for storage (just an integer), and universally understood across programming languages and systems. They're used in cookies, session management, cache expiration, rate limiting, job scheduling (like cron), audit trails, and anywhere precise time tracking is needed. The tool handles edge cases including very old dates (before 1970, which result in negative timestamps), far future dates, daylight saving time transitions, and leap seconds. Understanding Unix timestamps is essential for backend development, DevOps, data analysis, and debugging time-related issues in distributed systems. Works on all modern browsers including Chrome, Firefox, Safari, and Edge, on desktop, tablet, and mobile devices.